Mortars have long been used in military conflicts for relatively short range engagements. Mortars can be particularly useful in close engagements because of their ability to launch projectiles in high, parabolic trajectory with a near vertical descent. The mortar can land bombs on nearby targets, including those behind obstacles or in fortifications, such as light vehicles behind hills or structures, or infantry in trenches. Mortars and their ammunition are generally much smaller and lighter than vehicle mounted artillery allowing for easy transport and use by individual combatants on the battlefield.
Mortars are generally constructed with a steel tube for firing a projectile. The tube is attached to a base plate often by using a ball joint. The based plate is used to support the tube and act to absorb recoil when fired. In many mortar designs, a bipod with a transverse support bar is mounted to the tube and used to support the tube in an upright position. The bipod also provides a support structure for a threaded azimuth adjustment bar and a sight that allow a mortorman to aim the weapon.
Although some mortar sights have been mounted to the tube, such as is disclosed in U.S. Pat. Nos. 2,478,898 and 6,568,118, conventional mortar sights are typically mounted to the bipod and are designed to aim at pre-positioned aiming stakes, instead of directly at the target. U.S. Pat. Nos. 2,478,898 and 6,568,118 are fully incorporated herein by reference. In a conventional mortar system, the sight is typically mounted to the left side of the traverse of the bipod. These sights are designed to rotate side to side (deflection) and up and down (elevation). Target data is input to the sight by turning the deflection and elevation knobs to the desired number. The whole weapon system is then shifted so the sight is pointed at the aiming poles at which point the bipod is adjusted to level the bubble levels on the sighting device.
Handheld mortars are generally smaller, lighter weight, and are carried onto the battlefield by soldiers and marines. Typically handheld mortars do not have either a bipod or an attached aiming sight. Sighting handheld mortar is achieved by holding the tube below the muzzle and placing the thumb in line with the tube. The mortarman then aims his thumb at the desired target. The angle of fire is then adjusted using a range scale on the firing handle and the mortarman continues to adjust his aim with subsequent firing. Proficiency in aiming a handheld mortar is gain only through repetition and practice in firing.
Even with significant practice, aiming a handheld mortar in a battlefield scenario can be difficult and often results in projectiles missing their target, use of valuable ammunition and time. Wind, temperature, moisture and other environmental variables all come into play when properly aiming a mortar. Additionally, projectile weight, propellant type and temperature, tube ware and other physical variable effect trajectory.
Handheld mortars are also subject to improper aiming based on any change in the deflection of the mortar. If a ball joint is used to mount the tube to the base plate, as is the case in most contemporary handheld mortar systems, as the tube is moved horizontally the arch of the ball in the ball joint will cause the elevation of the tube to rise or fall based on the curvature of the ball joint. In mortars with a bipod this can be corrected for with the use of a bubble level that is horizontally mounted on the sight. If there is any change in the elevation when moving the tube horizontally, you can simply turn a vertical adjustment screw until the level is again balanced. However, in a handheld mortar, because there is not bipod or sight, there is also not level to use for maintaining horizontal position.
Therefore a need exists for a sighting system for a handheld mortar that provides solution to the aforementioned deficiencies in the prior art. The present teachings provide such a system. In view of the foregoing background, the present invention overcomes the limitations of the prior art by providing for a sight adapter for handheld mortar systems. Therefore it is an object of this disclosure to provide a sight adapter that can be easily retrofit onto existing mortar systems by fastening directly to the launch tube of a handheld mortar.
In another aspect of this invention, provided is a Mil-Std-1913 Picatinny standardized mounting rail interface for easy attachment of an existing optical weapon sight.
In yet another aspect of the invention a sight adapter is provided with an electronic tilt sensor for detecting the angle of inclination and tilt of the handheld mortar tube relative to the ground and converting the data to a target distance indication and displaying such information for easy use by the mortarman.
It is yet another aspect of the invention to provide a novel curved bubble level associated with the launch tube for providing rapid information regarding the vertical position of the tube.
In another aspect of the invention, launch tube tilt data along with projectile, propellant and environmental data is used to calculate projectile flight distance.
In one further aspect of the invention, projectile flight distance 1s readily displayed to the mortarman for quick and convenient determination of tube angle vs. target range.
These and other objects, features and advantages in accordance with the present invention are provided. These aspects of the invention are not intended to be exclusive and other features, aspects, and advantages of the present invention will be readily apparent to those of ordinary skill in the art when read in conjunction with the following description, appended claims and accompanying drawings.